import java.util.*;

class Shape {
    // Base method (to be overridden)
    public double area() {
        return 0;
    }

    // Overloaded versions
    public double area(double a) {
        return 0;
    }

    public double area(double a, double b) {
        return 0;
    }
}

class Circle extends Shape {
    double radius;

    Circle(double r) {
        this.radius = r;
    }

    // ✅ Overriding
    @Override
    public double area() {
        return Math.PI * radius * radius;
    }

    // ✅ Overloading
    public double area(double r) {
        return Math.PI * r * r;
    }
}

class Rectangle extends Shape {
    double length, width;

    Rectangle(double l, double w) {
        this.length = l;
        this.width = w;
    }

    @Override
    public double area() {
        return length * width;
    }

    public double area(double l, double w) {
        return l * w;
    }
}

class Square extends Shape {
    double side;

    Square(double s) {
        this.side = s;
    }

    @Override
    public double area() {
        return side * side;
    }

    public double area(double s) {
        return s * s;
    }
}

public class First {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String str = sc.next();

        if (str.equals("Circle")) {
            double rad = sc.nextDouble();
            if (rad < 0) {
                System.out.println("Invalid input");
                return;
            }
            Circle c = new Circle(rad);
            System.out.printf("%.2f\n", c.area()); // using overriding

        } else if (str.equals("Rectangle")) {
            double len = sc.nextDouble();
            double breadth = sc.nextDouble();
            if (len < 0 || breadth < 0) {
                System.out.println("Invalid input");
                return;
            }
            Rectangle r = new Rectangle(len, breadth);
            System.out.printf("%.2f\n", r.area());

        } else if (str.equals("Square")) {
            double side = sc.nextDouble();
            if (side < 0) {
                System.out.println("Invalid input");
                return;
            }
            Square s = new Square(side);
            System.out.printf("%.2f\n", s.area());

        } else {
            System.out.println("Invalid input");
        }
    }
}